A method for continuously assessing coronary blood flow velocity in the rat

Area of Science:

• Cardiovascular Physiology
• Biomedical Engineering
• Medical Imaging

Background:

• Coronary blood flow velocity (CBV) is crucial for assessing cardiac health.
• Accurate measurement of CBV in small animal models is challenging.
• Existing methods may require invasive procedures, limiting their application.

Purpose of the Study:

• To develop and validate a non-invasive directional pulsed-Doppler system for measuring rat coronary blood flow velocity (CBV).
• To assess the feasibility of using this system in disease models.
• To provide a tool for detailed characterization of the coronary circulation.

Main Methods:

• Development of a directional pulsed-Doppler system with a suction cup probe (1-mm2 crystal, 6-mm cup).
• Non-invasive attachment of the probe to the coronary artery via vacuum, avoiding dissection.
• Recording of phasic CBV and correlation with microsphere-measured left-ventricular perfusion.

Main Results:

• The system successfully measured phasic CBV in rats.
• 82% +/- 2% of CBV occurred during diastole.
• CBV increased with dipyridamole infusion and correlated with left-ventricular pressure.
• CBV measurements closely correlated with microsphere-measured perfusion (r = 0.93).

Conclusions:

• The developed Doppler system provides a reliable and non-invasive method for measuring rat coronary blood flow velocity (CBV).
• This technique facilitates detailed characterization of the coronary circulation in rat disease models.
• The system's accuracy and ease of use support its application in cardiovascular research.